With New York City finally ridding itself of the smells that only a nasty heat wave can incubate, and the Bay Area looking at a past heat wave of its own, people are starting to do the math.

And what they’re realizing is that, after living for hundreds of years without much of a care for the environment, the planet may be about to retaliate by giving us, and our children, and our children’s children, a future climate that we are wholly unprepared to face.

What’s hard to believe, though, is that some people are still in denial that global warming exists.

“Well, I say they’re wrong,” says Laurie David, an environmental activist who helped found the Stop Global Warming Virtual March, a movement to get individuals to use their collective voices to demand governments, corporations and politicians take the steps necessary to stop global warming. “And more than 2,000 scientists from 100 countries are right. There’s more consensus right now that global warming is real than there was that tobacco smoking caused cancer when that whole movement started.”

With David’s Virtual March, the focus is on the individual. Because what you eat, what you drive, how you build and furnish your home, can all make a difference in curbing global warming.

“Government doesn’t change until people demand it. It has to start with the individual,” says David, who lives in Los Angeles, and who spearheaded the Virtual march with Sen. John McCain and noted environmental lawyer Robert F. Kennedy, Jr. “If one person makes one change, chances are they’ll make two changes. And then their friends might make a change. We need agiant industrial revolution in this country. That’s why we need this Virtual March: One voice can turn into millions.”

Here are 10 tips to how your voice can be heard, courtesy of stopglobalwarming.org, the home of David’s Virtual March. Every tip listed here will reduce emissions of carbon dioxide, which is what most scientists say is a major contributor to global warming. Emissions- and cost-savings were calculated using the Stop Global Warming calculator.

1. Buy organic and local. Yes, there’s a reason to buy organic other than pleasing your really granola mother-in-law: The chemicals used in much of modern agriculture pollute the water supply and require energy to produce. Local foods also reduce the amount of energy required to drive your products to the store. Oh, and while you’re at it, bring cloth bags to the market to help reduce waste.

2. Air dry your clothes. Line-drying clothes during the non-rainy months instead of using a dryer can save 700 pounds of carbon dioxide, and, as a bonus, $75 a year.

3. Change light bulbs. “Compact fluorescent bulbs have such a terrible name, but they use 66 percent less energy,” says David. Replacing just three frequently used bulbs in your home can save 300 pounds of carbon dioxide and $60 a year.

4. Go hybrid, or at least think about MPG. “Look, we’re all car owners — you have to consider these hybrid cars,” says David. And for good reason: the average hybrid driver could save 16,000 pounds of carbon dioxide a year. Off-setting their higher sticker price is the fact that they can also save $3,750 in gas money. “Short of that, another big thing is to ask, when you buy a car, (think) about its mileage. That’s number one in my book,” adds David.

5. Inflate car tires and change the air filter. Improperly inflated tires can waste as much as 250 pounds of carbon dioxide a year and $840 in gas money. A tired air filter can also waste 800 pounds of carbon dioxide and $130 a year. Check both monthly.

6. Check the water heater or go tankless. Keeping a water heater thermostat at no higher than 120 degrees Fahrenheit saves money and reduces emissions. Insulating the water heater adds additional savings. Switching to a tankless water heater is even better, saving 300 pounds of carbon dioxide a year and $390.

7. Consider the shower. With showers accounting for two-thirds of all water heating costs, shorter time sudsing it up can save up to 350 pounds of carbon dioxide a year. Installing a low-flow showerhead saves another 350 pounds of carbon dioxide.

8. Unplug appliances. Even when a plugged-in electronic appliance is turned off, it can use energy. Play it safe and unplug them, and save more than 1,000 pounds of carbon dioxide and $256 a year.

9. Adjust the thermostat. Just two degrees up in summer and two degrees down in winter can save a whopping 2,000 pounds of carbon dioxide and $98 a year.

10. Plant a tree. What better way to go green than by planting a tree? Trees help suck up the carbon dioxide, provide cleaner air, and save 2,000 pounds of carbon dioxide a year.